main()
{
    int i,j,n=0,x;
    for(i=23; n==0; i+=2)
    {
        for(j=1, x=i; j<=4 && x>=11;j++)
        if((x+1) % (j+1) ==0)
           x -= (x+1)/(j+1);
        else {x=0; break; }
        if(j==5&& x==11)
        {
            printf("There are %d fishes at first. \n",i);
            n=1;
        }
        
    }
}